FIELD OF THE INVENTION
The invention relates to a method and an apparatus for attaching a web of material for translation through a rotary printing press system.
Single side web-up systems require measures for attaching a web to a guiding device (commonly known as a "snake"). Such measures generally take the form of a triangle (otherwise known as a kite). Side loads imposed by web tension across the web width are focused at the apex of the triangle, where the triangle is attached to the guiding device. Those side loads can cause the web to run off, or to cause wrinkling or tearing of the web.
Furthermore, the attachment of the triangle to the guiding device presents a problem in aligning the triangle relative to the intended web path so that offset loading and/or web displacement is avoided. Currently, triangles are joined to the guiding device at the apex of the triangle. That allows a rotational degree of freedom around which the triangle can pivot. That presents a problem when the attachment of the triangle is made to the web. Since the triangle is not fixed along the web path, it is difficult to align the triangle to the web. In addition, the edge of the triangle is difficult to locate so that it is coincident with the edge of the web.
The problem is compounded by restrictions which are imposed firstly by the small amount of space that an operator has to work in at a reel stand, and secondly by working on a round surface defined by the paper reel, as opposed to a preferably flat surface.
A conventional attachment of a guiding device to a web is shown in U.S. Pat. No. 5,039,742. In that device, a flexible pulling sheet which is attached to a web is secured to a pull-in element by attachment clamps. The pull-in element has a cable for threading the web through a printing machine.